Editor does not save font asset "fallback Reference" properly, which prevents the fallback from working

To reproduce:
1. Open attached project "Font Fallback Test.zip"
2. Open "init" scene.
3. There are 4 different examples of text. 3rd example's Japanese text should be falling back just like in 1st and 4th example (3rd and 4th examples are the same, but the 4th one is fixed inside it's metafile)